Home | History | Annotate | Download | only in launcher2 
      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.launcher2;
     18 
     19 import android.graphics.Bitmap;
     20 import android.graphics.BlurMaskFilter;
     21 import android.graphics.Canvas;
     22 import android.graphics.Paint;
     23 import android.graphics.PorterDuff;
     24 import android.graphics.PorterDuffXfermode;
     25 
     26 public class HolographicOutlineHelper {
     27     private final Paint mHolographicPaint = new Paint();
     28     private final Paint mBlurPaint = new Paint();
     29     private final Paint mErasePaint = new Paint();
     30 
     31     public static final int MAX_OUTER_BLUR_RADIUS;
     32     public static final int MIN_OUTER_BLUR_RADIUS;
     33 
     34     private static final BlurMaskFilter sExtraThickOuterBlurMaskFilter;
     35     private static final BlurMaskFilter sThickOuterBlurMaskFilter;
     36     private static final BlurMaskFilter sMediumOuterBlurMaskFilter;
     37     private static final BlurMaskFilter sThinOuterBlurMaskFilter;
     38     private static final BlurMaskFilter sThickInnerBlurMaskFilter;
     39     private static final BlurMaskFilter sExtraThickInnerBlurMaskFilter;
     40     private static final BlurMaskFilter sMediumInnerBlurMaskFilter;
     41 
     42     private static final int THICK = 0;
     43     private static final int MEDIUM = 1;
     44     private static final int EXTRA_THICK = 2;
     45 
     46     static {
     47         final float scale = LauncherApplication.getScreenDensity();
     48 
     49         MIN_OUTER_BLUR_RADIUS = (int) (scale * 1.0f);
     50         MAX_OUTER_BLUR_RADIUS = (int) (scale * 12.0f);
     51 
     52         sExtraThickOuterBlurMaskFilter = new BlurMaskFilter(scale * 12.0f, BlurMaskFilter.Blur.OUTER);
     53         sThickOuterBlurMaskFilter = new BlurMaskFilter(scale * 6.0f, BlurMaskFilter.Blur.OUTER);
     54         sMediumOuterBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.OUTER);
     55         sThinOuterBlurMaskFilter = new BlurMaskFilter(scale * 1.0f, BlurMaskFilter.Blur.OUTER);
     56         sExtraThickInnerBlurMaskFilter = new BlurMaskFilter(scale * 6.0f, BlurMaskFilter.Blur.NORMAL);
     57         sThickInnerBlurMaskFilter = new BlurMaskFilter(scale * 4.0f, BlurMaskFilter.Blur.NORMAL);
     58         sMediumInnerBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.NORMAL);
     59     }
     60 
     61     HolographicOutlineHelper() {
     62         mHolographicPaint.setFilterBitmap(true);
     63         mHolographicPaint.setAntiAlias(true);
     64         mBlurPaint.setFilterBitmap(true);
     65         mBlurPaint.setAntiAlias(true);
     66         mErasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
     67         mErasePaint.setFilterBitmap(true);
     68         mErasePaint.setAntiAlias(true);
     69     }
     70 
     71     /**
     72      * Returns the interpolated holographic highlight alpha for the effect we want when scrolling
     73      * pages.
     74      */
     75     public static float highlightAlphaInterpolator(float r) {
     76         float maxAlpha = 0.6f;
     77         return (float) Math.pow(maxAlpha * (1.0f - r), 1.5f);
     78     }
     79 
     80     /**
     81      * Returns the interpolated view alpha for the effect we want when scrolling pages.
     82      */
     83     public static float viewAlphaInterpolator(float r) {
     84         final float pivot = 0.95f;
     85         if (r < pivot) {
     86             return (float) Math.pow(r / pivot, 1.5f);
     87         } else {
     88             return 1.0f;
     89         }
     90     }
     91 
     92     /**
     93      * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
     94      * bitmap.
     95      */
     96     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
     97             int outlineColor, int thickness) {
     98         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, true,
     99                 thickness);
    100     }
    101     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    102             int outlineColor, boolean clipAlpha, int thickness) {
    103 
    104         // We start by removing most of the alpha channel so as to ignore shadows, and
    105         // other types of partial transparency when defining the shape of the object
    106         if (clipAlpha) {
    107             int[] srcBuffer = new int[srcDst.getWidth() * srcDst.getHeight()];
    108             srcDst.getPixels(srcBuffer,
    109                     0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
    110             for (int i = 0; i < srcBuffer.length; i++) {
    111                 final int alpha = srcBuffer[i] >>> 24;
    112                 if (alpha < 188) {
    113                     srcBuffer[i] = 0;
    114                 }
    115             }
    116             srcDst.setPixels(srcBuffer,
    117                     0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
    118         }
    119         Bitmap glowShape = srcDst.extractAlpha();
    120 
    121         // calculate the outer blur first
    122         BlurMaskFilter outerBlurMaskFilter;
    123         switch (thickness) {
    124             case EXTRA_THICK:
    125                 outerBlurMaskFilter = sExtraThickOuterBlurMaskFilter;
    126                 break;
    127             case THICK:
    128                 outerBlurMaskFilter = sThickOuterBlurMaskFilter;
    129                 break;
    130             case MEDIUM:
    131                 outerBlurMaskFilter = sMediumOuterBlurMaskFilter;
    132                 break;
    133             default:
    134                 throw new RuntimeException("Invalid blur thickness");
    135         }
    136         mBlurPaint.setMaskFilter(outerBlurMaskFilter);
    137         int[] outerBlurOffset = new int[2];
    138         Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
    139         if (thickness == EXTRA_THICK) {
    140             mBlurPaint.setMaskFilter(sMediumOuterBlurMaskFilter);
    141         } else {
    142             mBlurPaint.setMaskFilter(sThinOuterBlurMaskFilter);
    143         }
    144 
    145         int[] brightOutlineOffset = new int[2];
    146         Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
    147 
    148         // calculate the inner blur
    149         srcDstCanvas.setBitmap(glowShape);
    150         srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
    151         BlurMaskFilter innerBlurMaskFilter;
    152         switch (thickness) {
    153             case EXTRA_THICK:
    154                 innerBlurMaskFilter = sExtraThickInnerBlurMaskFilter;
    155                 break;
    156             case THICK:
    157                 innerBlurMaskFilter = sThickInnerBlurMaskFilter;
    158                 break;
    159             case MEDIUM:
    160                 innerBlurMaskFilter = sMediumInnerBlurMaskFilter;
    161                 break;
    162             default:
    163                 throw new RuntimeException("Invalid blur thickness");
    164         }
    165         mBlurPaint.setMaskFilter(innerBlurMaskFilter);
    166         int[] thickInnerBlurOffset = new int[2];
    167         Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
    168 
    169         // mask out the inner blur
    170         srcDstCanvas.setBitmap(thickInnerBlur);
    171         srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
    172                 -thickInnerBlurOffset[1], mErasePaint);
    173         srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
    174                 mErasePaint);
    175         srcDstCanvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1],
    176                 mErasePaint);
    177 
    178         // draw the inner and outer blur
    179         srcDstCanvas.setBitmap(srcDst);
    180         srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
    181         mHolographicPaint.setColor(color);
    182         srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
    183                 mHolographicPaint);
    184         srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
    185                 mHolographicPaint);
    186 
    187         // draw the bright outline
    188         mHolographicPaint.setColor(outlineColor);
    189         srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
    190                 mHolographicPaint);
    191 
    192         // cleanup
    193         srcDstCanvas.setBitmap(null);
    194         brightOutline.recycle();
    195         thickOuterBlur.recycle();
    196         thickInnerBlur.recycle();
    197         glowShape.recycle();
    198     }
    199 
    200     void applyExtraThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    201             int outlineColor) {
    202         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, EXTRA_THICK);
    203     }
    204 
    205     void applyThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    206             int outlineColor) {
    207         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, THICK);
    208     }
    209 
    210     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    211             int outlineColor, boolean clipAlpha) {
    212         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, clipAlpha,
    213                 MEDIUM);
    214     }
    215 
    216     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    217             int outlineColor) {
    218         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, MEDIUM);
    219     }
    220 
    221 }
    222